Conventionally, there has been known a satellite digital radio broadcast that uses an artificial satellite to deliver music information as an audio signal for music and identification information about the music such as tune name, artist name, category name, and data size (or replay time).
The satellite digital radio broadcast can detect a tune name or an artist name of the currently broadcast music from the identification information. A display device for displaying the information is generally provided for an audio apparatus that receives the broadcast and generates sounds (e.g., see Patent Document 1).
Conventionally, the following apparatus for recording broadcast signals is proposed (e.g., see Patent Document 2). The recording apparatus temporarily records a received broadcast signal on a recording medium. The apparatus determines whether or not a user needs to record the temporarily recorded broadcast signal as music. When the user needs to record that music, the apparatus finally records the music from the beginning using the temporarily recorded broadcast signal.
When the proposed recording apparatus is built in an audio apparatus for receiving the satellite digital radio broadcast, the user can record the currently broadcast music from the beginning by listening to the radio broadcast (music) and entering a recording instruction. Since the display device displays identification information about the on-air music, the user can record a favorite artist's tune by viewing the display.
(First Problem)
When the music information is acquired from the radio broadcast and is recorded on a recording medium, an electromagnetic interference such as fading may interrupt the recording in the middle of the music (tune). An audio apparatus mounted in a mobile object is often subject to this problem. Such audio apparatus interrupts the recording in the middle of a tune when a mobile object enters a place where no radio is available, or reaches a destination to turn off the audio apparatus.
When the recording is interrupted in the middle of one tune and the user is unaware of this during the recording, the user does not notice the interrupted recording until replaying the recorded tune. Even when the user notices the interrupted recording, the user needs to wait for the interrupted music (tune) to be replayed by listening to the satellite digital radio broadcast. When the intended tune is broadcast, the user needs to reenter a recording instruction. Re-recording the music (tune) is cumbersome and time-consuming.
(Second Problem)
An audio apparatus having a radio reception function and a recording function generally stops a radio reception unit while replaying a recorded tune or generating an audio (music) from an information source other than the radio unit such as music tape, music CD, and MD.
The audio apparatus receiving the satellite digital radio broadcast may be provided with the recording function and may generate a sound other than that from the radio set. In such case, even though the satellite digital radio broadcast supplies the music the user wants to record, he or she cannot notice it and loses a chance to record the music.
Patent Document 2 solves this problem by constructing the audio apparatus (recording apparatus) as follows. The audio apparatus compares a user-registered recording keyword (recording information such as an artist name or a category) with identification information about the music delivered by the satellite digital radio broadcast. In this manner, the audio apparatus detects the broadcast of the music (tune) the user wants to record and automatically records the on-air music (tune) during the detection.
To do this, however, the user needs to enter a keyword for recording and feels this operation bothersome. Entering the keyword automatically records only the music (tune) that matches the keyword. The user cannot always record the music (tune) he or she wants.
(Third Problem)
As mentioned above, the satellite digital radio broadcast delivers not only the music information but also the identification information about the music. The audio apparatus capable of receiving and recording the broadcast records both the received music information and identification information on a recording medium. The audio apparatus therefore allows the user to easily retrieve intended music information from the recorded information using the identification information (e.g., see Patent Documents 2 and 3).
Another known audio apparatus acquires music information from an information source such as a music CD other than the radio broadcast and supplies identification information to the music information for recording on a recording medium. After the recording, targeted music information can be easily retrieved.
When a conventional audio apparatus generates a sound based on the music information delivered by the satellite digital radio broadcast, the apparatus can notify the user of the currently played music's tune name or artist name using the identification information delivered along with the music information. While reproducing the music information recorded on a recording medium, the apparatus can notify the user of the currently played music's tune name or artist name using the identification information recorded with the music information. However, the apparatus cannot notify the user of the relationship between the on-air music and the music recorded on the recording medium.
For example, the user may listen to the recorded music during the broadcast of another piece of music belonging to a category the user is interested in. The user cannot notice the music of that category was broadcast.
Even though the radio broadcast delivers the music information for audio output and the identification information representing the category, the identification information is not used effectively.                Patent Document 1: JP-2006-109233 A        Patent Document 2: JP-2005-332475 A        Patent Document 3: JP-2004-80275 A        